Plots in polar coordinates, Plots in polar coordinates ,12-18 – HP 50g Graphing Calculator User Manual

Page 401

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Page 12-18

the corresponding values of f(x), listed as Y1 by default. You can use the
up and down arrow keys to move about in the table. You will notice that
we did not have to indicate an ending value for the independent variable
x. Thus, the table continues beyond the maximum value for x suggested
early, namely x = 5.

Some options available while the table is visible are

@ZOOM, @@BIG@, and @DEFN:

Θ The @DEFN, when selected, shows the definition of the independent variable.
Θ The @@BIG@ key simply changes the font in the table from small to big, and

vice versa. Try it.

Θ The @ZOOM key, when pressed, produces a menu with the options: In, Out,

Decimal, Integer, and Trig. Try the following exercises:

Θ With the option In highlighted, press @@@OK@@@. The table is expanded so

that the x-increment is now 0.25 rather than 0.5. Simply, what the
calculator does is to multiply the original increment, 0.5, by the zoom
factor, 0.5, to produce the new increment of 0.25. Thus, the zoom in
option is useful when you want more resolution for the values of x in
your table.

Θ To increase the resolution by an additional factor of 0.5 press @ZOOM,

select In once more, and press

@@@OK@@@. The x-increment is now 0.0125.

Θ To recover the previous x-increment, press @ZOOM —@@@OK@@@ to select the

option Un-zoom. The x-increment is increased to 0.25.

Θ To recover the original x-increment of 0.5 you can do an un-zoom

again, or use the option zoom out by pressing

@ZOOM @@@OK@@@.

Θ The option Decimal in @ZOOM produces x-increments of 0.10.
Θ The option Integer in @ZOOM produces x-increments of 1.
Θ The option Trig in produces increments related to fractions of

π

, thus

being useful when plotting trigonometric functions.

Θ To return to normal calculator display press `.

Plots in polar coordinates

First of all, you may want to delete the variables used in previous examples
(e.g., X, EQ, Y1, PPAR) using function PURGE (I

@PURGE). By doing this, all

parameters related to graphics will be cleared. Press J to check that the
variables were indeed purged.

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